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The back cusk eel, Genypterus maculatus (Tschudi, 1846), (Ophiidiformes: Ophiididae) is one of the benthic-demersal fish usually consumed in northern Peru. Here, we identified the third stage (L3) Anisakidae sampled from 29 specimens of G. maculatus captured off the south American Pacific coast, Lambayeque Region, Peru. A total of 20 anisakid nematode larvae were collected on the visceral surface and divided morphologically into three types (Type I–III). These larvae were identified by mtDNA Cox2 sequences analysis, which indicated that corresponded to Anisakis pegreffii Campana-Rouget and Biocca, 1955, Skrjabinisakis physeteris (Baylis, 1923) and S. brevispiculata (Dollfus, 1966) Safonova, Voronova, and Vainutis, 2021, respectively. This is the first record of S. brevispiculata in Peru. The results obtained in this study provide knowledge on the diversity and distribution of Anisakis Dujardin, 1845 and Skrjabinisakis Mozgovoi, 1951, species in the south American Pacific waters and their relevance for public health. In addition, we suggest that combined use of molecular and morphological approaches is needed to characterize L3 anisakid larvae. [ABSTRACT FROM AUTHOR]

The dynamically growing incidence of food allergies forces the scientific community to develop new methods for their diagnosis, differentiation, and effective treatment. Parasitoses appear much less frequently in the scientific literature, as well as among the presumed causes of numerous conditions. The similarity of inflammatory mechanisms in allergies and parasitosis necessitates a revision of current diagnostic standards. A lack of specificity and the coincidence of symptoms at an early stage of disease can lead to misdiagnosis. In this paper, we attempted to perform a comparative analysis of the similarities and differences in symptoms for these two types of diseases. We described the molecular mechanisms and metabolic pathways of food allergy and parasitosis. We presented the available research methods and directions of ongoing studies aimed at implementing precise medical techniques for differential diagnosis. We discussed the allergenic properties of certain parasite proteins, using the example of myofibrillar tropomyosins from the nematode Anisakis simplex. The literature in the fields of allergology and parasitology leads to the conclusion that it is reasonable to run parallel allergological and parasitological diagnostics in patients with non-specific symptoms. This approach will facilitate accurate and early diagnosis and implementation of effective therapy. [ABSTRACT FROM AUTHOR]

Using data from 2018–2019 health insurance claims, we estimated the average annual incidence of anisakiasis in Japan to be 19,737 cases. Molecular identification of larvae revealed that most (88.4%) patients were infected with the species Anisakis simplex sensu stricto. Further insights into the pathogenesis of various anisakiasis forms are needed.

Anisakiasis is an arising zoonosis induced by parasitic nematodes belonging to the family Anisakidae. Anisakiasis is often caused by the ingestion of larval nematodes in uncooked or minimally processed seafood dishes, which are regularly consumed by humans. Significant potential sources of infection are raw fish (e.g., sushi and sashimi) that can be found in traditional Japanese cuisine and can be part of the culinary tradition of consumption of raw or marinated fish that is particularly diffused in European countries. During the last five decades, the global prevalence of human anisakiasis has been rising, becoming an emergent major public health problem. Thus, there is an unmet need for well-defined and cost-effective methods aimed at killing Anisakis larvae, thus reducing the incidence of anisakiasis. In this mini-review, we discuss the clinical features of anisakiasis as well as the effectiveness and mechanisms of action of the main methods employed for increasing seafood safety and killing Anisakis larvae, including freezing, heating, use of high hydrostatic pressure, salting process, pepsin digestion method and use of garlic oil. [ABSTRACT FROM AUTHOR]

The rising popularity of undercooked or raw seafood containing larvae of the Anisakis parasite has led to issues of public health concern due to allergic manifestations. We conducted an observational study on the use of an innovative Anisakis allergy diagnostic algorithm in a convenience sample of 53 allergic outpatients recruited in Western Sicily, between April 2021 and March 2022. We included individuals with an anamnesis suggestive of IgE sensitization to Anisakis reporting clinical manifestation in the last month due to allergic reactions after eating fresh fish, or in subjects at high exposure risk with sea products while abstaining from fish ingestion, excluding those with documented fish sensitization. Outpatients were tested via Skin Prick Test, IgE-specific dosage and Basophil Activation Test (BAT). Twenty-six outpatients were diagnosed with Anisakis, while 27 with Chronic Urticaria (CU). We found a seven-fold excess risk for Anisakis (p4) positivity in the Anisakis allergic outpatients, as compared to the CU ones. BAT showed the best diagnostic accuracy (92.45%) and specificity (100%), while specific IgE to Ascaris (p1) documented the best sensitivity (92.31%) but a very low specificity (37.04%). In conclusion, our findings may represent a potentially useful contribution to the future development of updated clinical guidelines. [ABSTRACT FROM AUTHOR]

The study of the zoonotic parasites of the genus Anisakis and human anisakiasis is an increasingly hot topic in evolutionary biology and epidemiological studies carried out on natural and accidental (human) hosts, given the risk of this parasite to human health. However, the assessment of social-psychological factors relevant to Anisakis' risky consumption of human behavior is still an understudied topic. Given the centrality of the topic, highlighted by its presence in Goals 2 (subgoal 2.1, achieve food security and improve safe nutrition) and 3 (health and well-being) of the 2030 Agenda, it appears necessary to deepen our social-psychological knowledge regarding this specific topic. There is plenty of psychological research focused on antecedents of fish and seafood consumption; however, parasite risk is not often specifically examined. This research is aimed at increasing the safety of consumers' seafood products by examining their psychological aspects, such as knowledge, perception, awareness, and concern about Anisakis. Past and future behavior intentions were also investigated. Analyses were carried out on a sample of 251 subjects, and a path analysis model was used to explain possible relations assumed among the variables. The results of the study showed that habits related to raw fish consumption and self-perceived health were, respectively, positively, and negatively correlated with a higher perceived risk of contracting anisakiasis. This perceived risk in turn correlates positively with a greater willingness to pay for Anisakis-free fish. Similarly, prior knowledge of the disease was found to be associated with prior avoidance of fish consumption, which in turn was found to be positively correlated with a greater willingness to pay for Anisakis-free fish. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, a drop in the condition of the European sardine has been observed. Although several causes have been attributed to this issue, as overfishing and climate change, little is known about the link between ascaridoid nematode parasitisation and fish status. In this study, sardines were obtained from four fishing grounds along the Mediterranean (Alboran, Northern Spain, Northern Adriatic, and Aegean), and one location in the Atlantic Ocean (Southern Portugal). After analysing individual fish body condition (by direct tissue fat content measurements and condition indices), and reproductive status (by a detailed gonadal examination) throughout the entire annual cycle, ascaridoids were recognised by combining naked eye and UV-press method along flesh, viscera, and gonads. Afterwards, sequence analysis of the rDNA internal transcribed spacers region (ITS) and the mtDNA cox2 gene were used to identify and characterise the different species of ascaridoids from the fish host in the localities throughout the seasons. The main species found along different areas was Hysterothylacium aduncum , present in the Northern Adriatic (prevalence of 7.6%, mean intensity 1.700), the Atlantic (7.5%, 3.889), and the Northern Spain (3.9%, 1.600). Moreover, few individuals of Anisakis simplex (s.s.) and A. pegreffii were observed in the Atlantic (1.7% and 0.8%, respectively), and the latter species was also found in the Adriatic stock (0.8%). All ascaridoid specimens were found in viscera. Obtained results seem to indicate that in stocks with medium sizes, small variations in length are related to parasite intensity. This study highlights the importance of seasonal parasitological analyses at stock level and, especially, in capital breeders, as relationships between condition and reproduction parameters and parasitism are conditioned by seasonality. [Display omitted] • The main ascaridoid species found in sardine stocks was Hysterothylacium aduncum. • Species of the genus Anisakis were observed in the Atlantic and the Adriatic. • Negative link nematode load-host condition but potentially affected by seasonality. • Non-parasitised stocks (Alboran and Aegean) had different reproductive phenology. • Small length variations in medium-size sardines were related with their nematode load. [ABSTRACT FROM AUTHOR]

Copyright of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Ürünleri Dergisi is the property of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Urunleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The longjaw tapertail anchovy Coilia nasus, which migrates from ocean to freshwater for spawning in spring, is an important anadromous fish with ecological and cultural significance. To determine parasite infection in anadromous C. nasus, a total of 103 fish from the Yangtze River were collected and examined in 2021 and 2022. The overall infection prevalence of nematodes in C. nasus was 100%, with a mean intensity of 13.81 ± 16.45. The mean intensity of nematode infections in 2022 was significantly higher than that observed in 2021 across all sampling sites (p < 0.05). Nematodes were widely detected in the mesentery, pyloric cecum, stomach, and liver, among which the mesentery accounted for the highest proportion, reaching up to 53.52%. A total of eight ascaridoid nematodes belonging to the family Anisakidae and Raphidascarididae were identified by using morphological characters and molecular biological techniques, including two species of Anisakis, five species of Hysterothylacium, and one species of Raphidascaris. A. pegreffii was found as the predominant species, accounting for 48.65% of all identified parasitic nematodes in liver, while Raphidascaris sp. was the most common nematode in the mesentery, pyloric cecum, and stomach, reaching up to 39.81%, 36.21%, and 74.36%, respectively. The present study systematically investigated the parasitic status and community structure of the nematode in C. nasus during its migration in the Yangtze River. This research provides a foundation for studying the impact of nematode parasitism on the reproductive migration and population recruitment of C. nasus, and offers valuable insights for biomarker screening and nematode identification in C. nasus.

Consumption of raw and mildly processed seafood, in the context of modern Western world eating trends, is recognized as a major driver for human fish-borne infections. However, these zoonoses and their unfamiliar risks remain neglected and underappreciated among European diagnosticians. In contemporary Europe anisakidosis is one of the most important fish-borne zoonoses. It is caused by ingesting the third-stage infective larvae of the nematode parasites that belong to the family Anisakidae. The case described herein, is an intestinal and ectopic form of anisakiosis (Anisakis spp.), causing symptoms of subacute abdomen and masquerading as an intraperitoneal malignancy. It is the first anisakidosis case reported in Greece, affecting a young patient who had been repeatedly exposed to the parasite by consuming homemade raw fish. Right hemicolectomy, omentectomy and excision of a descending colon nodule were uneventfully performed. The pathology report confirmed granulomatous tissue with eosinophilic infiltration and parasites that were morphologically and molecularly identified as Anisakis spp. Although challenging, acquiring an accurate diagnosis of anisakidosis can prevent unnecessary surgery, as the infection typically is self-resolving, and if treatment is deemed necessary, it can be limited to antiparasitic medication. However, in rare cases, extra-gastrointestinal migration of larvae can cause severe damage with practically unknown risks, posing a diagnostic and therapeutic dilemma. In such a clinical case scenario, surgical exploration can decisively contribute to a definitive diagnosis and early identification of intraabdominal complications necessitating surgical intervention.

Objective: Fish is a valuable food source and employment in developing countries. However, par¬asitic infections pose a threat to fish cultivation and fish health. This study is aimed at assessing intestinal parasites associated with marine fishes. Materials and Methods: A total of 30 frozen marine fishes, comprising 10 Clupea harengus (her¬rings), 10 Scomber scombrus (mackerel), and 10 Micromesistius poutassou (blue whiting) of dif¬ferent sizes and weights, were examined for intestinal parasites. Results: The results revealed Eimeria spp. and Goussia spp. as parasitic protozoa in M. poutassou and S. scombrus, respectively. Grillotia smarisgora was the only parasitic cestode in M. poutas¬sou. At the same time, Hemiurus spp. and Anisakis spp. were parasitic trematode and nematode observed in both C. harengus and S. scombrus fishes, respectively. Anisakis spp., a parasitic nema¬tode, was the most common intestinal parasite among the marine fishes with 70%, 80%, and 90% occurrence in S. scombrus, C. harengus, and M. poutassou, respectively. Conclusion: Parasitic infection is one of the factors undermining fish production. Therefore, fish sellers should be enlightened to improve sanitation in handling and processing fish. [Vet. Res. Notes 2022; 2(7.000): 54-59]

Atlantic cod (Gadus morhua) is an important commercial fish species on the world market. The aim of our studies was to explore the presence, intensity of infection and distribution of the zoonotic nematodes of the different genera of Anisakidae in the muscle tissue of G. morhua from the Norwegian Sea. Cod from fishing areas FAO IIa1 (n = 50) and FAO IIa2 (n = 56) were sampled in March 2017. The unskinned flesh of each fish was examined using a white-light transilluminator. Collected parasites were identified to the genus level, and a subsample was identified using molecular methods. We found a higher prevalence of infection with Anisakis than with Pseudoterranova in the musculature of cod from both fishing areas. In FAO IIa1, a lower prevalence of infection with Pseudoterranova was recorded (14%) than in FAO IIa2 (∼39%). However, the intensity of infection was higher (53) in FAO IIa2 than in FAO IIa1 (8 parasites per fish). The opposite was found with Anisakis (prevalence 88% in FAO IIa1 and ∼55% in FAO IIa2, intensity up to 30 and up to 25 parasites per fish respectively). Most Anisakis larvae were present in the belly flaps (predominantly the left side), while Pseudoterranova spp. were dispersed with descending frequency in belly flaps, dorsal fillet and caudal fillet. Molecular identification revealed the presence of A. simplex (s.s.), P. decipiens (s.s.) and P. krabbei in both areas, and a hybrid of P. decipiens and P. krabbei in FAO IIa2.

Introduction: Anisakis pegreffii is a sibling species within the A. simplex (s.l.) complex requiring marine homeothermic (mainly cetaceans) and heterothermic (crustaceans, fish, and cephalopods) organisms to complete its life cycle. It is also a zoonotic species, able to accidentally infect humans (anisakiasis). To investigate the molecular signals involved in this host-parasite interaction and pathogenesis, the proteomic composition of the extracellular vesicles (EVs) released by the third-stage larvae (L3) of A. pegreffii, was characterized. Methods: Genetically identified L3 of A. pegreffii were maintained for 24 h at 37° C and EVs were isolated by serial centrifugation and ultracentrifugation of culture media. Proteomic analysis was performed by Shotgun Analysis. Results and discussion: EVs showed spherical shaped structure (size 65-295 nm). Proteomic results were blasted against the A. pegreffii specific transcriptomic database, and 153 unique proteins were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis predicted several proteins belonging to distinct metabolic pathways. The similarity search employing selected parasitic nematodes database revealed that proteins associated with A. pegreffii EVs might be involved in parasite survival and adaptation, as well as in pathogenic processes. Further, a possible link between the A. pegreffii EVs proteins versus those of human and cetaceans' hosts, were predicted by using HPIDB database. The results, herein described, expand knowledge concerning the proteins possibly implied in the host-parasite interactions between this parasite and its natural and accidental hosts. [ABSTRACT FROM AUTHOR]

Anisakidae nematodes, especially Contracaecum osculatum, Anisakis simplex, and Pseudoterranova decipiens, have dispersed throughout the Baltic Sea over the last decade. Despite the fact that salmon, Salmo salar, is a popular choice among consumers and therefore one of the most valuable Baltic fish species, information about the level of infection of salmon liver with these zoonotic nematodes is sparse. In 2020, a total of 120 salmon livers were inspected for the presence of parasites showing that 13% of salmon livers were infected with C. osculatum. Furthermore, a single Pseudoterranova sp. larva was detected in one salmon liver, representing a host-parasite system that has never previously been reported in the Baltic Sea. [ABSTRACT FROM AUTHOR]

Anisakidosis is a foodborne zoonotic infection induced by members of the family Anisakidae via the consumption of raw or undercooked fish such as sushi and sashimi. Identifying anisakid larval species is critical for the epidemiology and diagnosis of diseases caused by them. This study aimed at identifying Anisakis larvae collected from marine fish in Egyptian waters based on morphological characteristics and molecular analysis. Thirty marine fish coral trout, Plectropomus areolatus, were collected from Hurghada, Red Sea, Egypt, to investigate larval nematodes of the genus Anisakis. The larvae were detected encapsulated in the peritoneal cavity and muscle of the fish host. This examination revealed that anisakid larvae naturally infected 19 fish specimens with a prevalence of 63.33% and a mean intensity of 4.1 ± 0.40. Most of them (68 larvae: 71.57%) were found in the musculature. Morphological and morphometric analyses using light and scanning electron microscopy revealed a head region with a prominent boring tooth, inconspicuous lips, and a characteristic protruded cylindrical mucron. All larvae in this study possessed the same morphology as Anisakis Larval type I. Molecular analysis based on ITS region using maximum likelihood and Bayesian phylogenetic methods confirmed them as Anisakis typica. This is the first study to identify A. typica larvae from the commercial fish coral trout P. areolatus in Egyptian waters using morphological and molecular methods. [ABSTRACT FROM AUTHOR]

Anisakiasis of the gastrointestinal tract is caused by the consumption of raw or undercooked seafood infected with Anisakis larvae. Penetration of Anisakis larvae into the gastrointestinal mucosa leads to severe epigastric pain, nausea, and vomiting, usually within hours of ingestion of the parasite. Suspicion for gastrointestinal Anisakiasis should be raised in patients with a compatible dietary history. Definitive diagnosis can be made by direct visualization of larvae via endoscopic examination. Although symptoms are self-limiting, the removal of larvae by gastroscopy can hasten relief of symptoms. There are a large number of cases of gastric anisakiasis reported from Japan, Korea, and Western Europe, where it is customary to consume raw fish. Cases reported from the United States are less common, and given the nonspecific symptoms of anisakiasis, the diagnosis can be missed. We report a patient who presented with gastroesophageal reflux disease like symptoms that started after ingesting raw fish. He was found by esophagogastroduodenoscopy to have white, filiform worms penetrating into the wall of his stomach, consistent with a diagnosis of gastric anisakiasis. [ABSTRACT FROM AUTHOR]

Background: Anisakiasis is a foodborne disease caused by the third-stage larvae (L3) of two species belonging to the genus Anisakis: Anisakis pegreffii and Anisakis simplex sensu stricto. Both species have been the subject of different -omics studies undertaken in the past decade, but a reliable in vitro culture protocol that would enable a more versatile approach to functional studies has never been devised. In nature, A. pegreffii shows a polyxenous life-cycle. It reproduces in toothed whales (final host) and disseminates embryonated eggs via cetacean faeces in the water column. In the environment, a first- (L1) and second-stage larva (L2) develops inside the egg, and subsequently hatched L2 is ingested by a planktonic crustacean or small fish (intermediate host). In the crustacean pseudocoelom, the larva moults to the third stage (L3) and grows until the host is eaten by a fish or cephalopod (paratenic host). Infective L3 migrates into the visceral cavity of its paratenic host and remains in the state of paratenesis until a final host preys on the former. Once in the final host's gastric chambers, L3 attaches to mucosa, moults in the fourth stage (L4) and closes its life-cycle by becoming reproductively mature. Methods: Testing two commercially available media (RPMI 1640, Schneider's Drosophila) in combination with each of the six different heat-inactivated sera, namely foetal bovine, rabbit, chicken, donkey, porcine and human serum, we have obtained the first reliable, fast and simple in vitro cultivation protocol for A. pegreffii. Results: Schneider's Drosophila insect media supplemented with 10% chicken serum allowed high reproducibility and survival of adult A. pegreffii. The maturity was reached already at the beginning of the third week in culture. From collected eggs, hatched L2 were maintained in culture for 2 weeks. The protocol also enabled the description of undocumented morphological and ultrastructural features of the parasite developmental stages. Conclusions: Closing of the A. pegreffii life-cycle from L3 to reproducing adults is an important step from many research perspectives (e.g., vaccine and drug–target research, transgenesis, pathogenesis), but further effort is necessary to optimise the efficient moulting of L2 to infective L3. [ABSTRACT FROM AUTHOR]

Simple Summary: The nematodes of the genus Anisakis are among the most prevalent parasites found in fishes and marine mammals and they are the main cause of human anisakiasis. Genetic studies have described two species, A. simplex and A. pegreffii, in European waters parasitizing several hosts, being the European hake, by far, the fish with higher infection values. The aim of this study is to enhance the knowledge of the distribution and population structure of the Anisakis species infecting hakes from the major European fishing areas through the use of genetic analysis. This study provides useful information about the genetic diversity of these parasites in the different fishing areas and fish tissues, valuable findings to understand the parasite speciation to different hake tissues and how they are structured along European waters. The European hake, one of the most commercially valuable species in ICES fishing areas, is considered an important neglected source of zoonotic risk by nematode parasites belonging to the genus Anisakis. Merluccius merluccius is, by far, the most important host of Anisakis spp. at the European fishing grounds, in terms of demographic infection values, and carries the highest parasite burden. These high parasite population densities within an individual fish host offer a chance to explore new sources of variations for the genetic structure of Anisakis spp. populations. A total of 873 Anisakis spp. third-stage larvae, originally sampled from viscera and muscular sections of hake collected at ten fishing grounds, were primarily identified using ITS rDNA region as molecular marker. After that, we used mtDNA cox2 gene to reveal the high haplotype diversity and the lack of genetic structure for A. simplex. Dominant haplotypes were shared among the different fishing areas and fish sections analyzed. Results indicate a clear connection of A. simplex from European hake along the Northern North Sea to the Portuguese coast, constituting a single genetic population but revealing a certain level of genetic sub-structuring on the Northwest coast of Scotland. This study also provides useful information to advance the understanding of parasite speciation to different fish host tissues or microenvironments. [ABSTRACT FROM AUTHOR]

Larvae of the nematode family Anisakidae are capable of causing parasitic infections in humans associated with the consumption of fishery products, leading to intestinal syndromes and allergic reactions. Anisakidae larvae are widely distributed geographically, with rates of parasitism close to 100% in certain fish species. Methods need to be established for their inactivation and elimination, especially in fishery products that are to be consumed raw, pickled, or salted, or which have been insufficiently treated to kill the parasite. Many strategies are currently available (such as freezing and heat treatment), but further ones, such as pulsed electric fields (PEF), have hardly been investigated until now. This study focuses on the experimental evaluation of the efficacy of PEF in the inactivation of Anisakis spp. larvae in terms of electric field strength, specific energy, and pulse width, as well as on the evaluation of the quality of fish samples after PEF treatment. Results show that viability of Anisakis was highly dependent on field strength and specific energy. Pulse width exerted a considerable influence at the lowest field strengths tested (1 kV/cm). Central composite design helped to define a PEF treatment of 3 kV/cm and 50 kJ/kg as the one capable of inactivating almost 100% of Anisakis present in pieces of hake, while affecting the investigated quality parameters (moisture, water holding capacity, and cooking loss) to a lesser extent than freezing and thawing. These results show that PEF could serve as an alternative to traditional freezing processes for the inactivation of Anisakis in fish. [ABSTRACT FROM AUTHOR]

In 2018, human anisakiasis caused by the ingestion of the skipjack tuna Katsuwonus pelamis occurred frequently in Japan. This may be attributable to a heavy infection of A. simplex (s.s.) in the host's muscle tissue. In this study, we investigate infection levels of anisakid L3 larvae in skipjack tuna captured in Japanese waters afterward (2019–2020) to contribute to predict and prevent the outbreak of human anisakiasis. A total of 476 larvae were detected from 78 out of 85 skipjack tuna captured at 14 stations of the Pacific and East China Sea. The present parasitological survey suggests that infection levels in 2019–2020 were low, comparing that in 2018; in total only seven larvae were found from the host's muscle tissue. The collected larvae were identified by molecular methods to Anisakis berlandi , A. pegreffii , A. simplex (s.s.), A. typica and Skrjabinisakis physeteris (s.l.). Not only larvae of A. simplex (s.s.) but also those of A. berlandi were found from the muscle tissue and thus the latter species may also be a causative agent of human anisakiasis. In addition, this study confirmed the geographic distribution pattern that A. simplex (s.s.) is abundant in the Pacific, while A. pegreffii is dominant in the East China Sea. Our results contribute to understanding the risk of food poisoning and stock delimitation of host animals. [Display omitted] • Anisakid larvae of Japanese skipjack tuna were investigated in 2019–2020. • A few larvae parasitized the host's muscle tissue investigated. • Not only Anisakis simplex (s.s.) but also A. berlandi was detected from the muscle tissue. [ABSTRACT FROM AUTHOR]

This article, published in the American Journal of Gastroenterology, discusses a rare case of asymptomatic colonic anisakis infiltration in a post-endoscopic mucosal resection scar. The patient, a 68-year-old man, had undergone colonoscopy and subsequent endoscopic mucosal resection for polyps and sessile serrated lesions. During a follow-up colonoscopy, an anisakis was found to have penetrated the previous scar. The patient had no symptoms or physical abnormalities, but had consumed raw fish prior to the incident. The article highlights the rarity of asymptomatic colonic anisakis cases and the unique nature of the infiltration in the scar. [Extracted from the article]

There is increasing information on the time-temperature conditions that can be lethal for Anisakis larvae, but little is known about the infective potential of larvae that survive heat treatments. To characterize the risks associated with accidentally undercooked fish, in this paper, more than 5000 Anisakis larvae in the third stage (L3) were individually treated, at quasi-isothermal conditions, in a thermal cycler at 50 °C for different exposure times (0–320 s). After heat exposition, surviving larvae were collected and their locomotor activity, resistance to simulated gastric juice (SGJ), agar penetrative ability, and respiration capacity were evaluated. Results show that, even after relatively short treatments that rendered survival ratios (S t 50 ° C ) close to 1 (i.e. all alive), some behavioral and physiological characteristics can be considerably impacted. Thus, L3 locomotor activity and agar penetrative ability significantly decreased after 60 s at 50 °C (S 60 s = 1), while heat expositions for 90 s (S 90 s ≈ 0.98) also reduced the resistance to SGJ and the respiration capacity. Our study reveals that the behavior of heat-treated Anisakis larvae depends on the intensity of the treatment and the longer the exposure time at 50 °C, the greater the changes observed in all the tested indicators. Further research is needed to elucidate the implications of the decline of these indicators on infectivity. • Survival ratio (S) of Anisakis larvae (L3) treated at 50 °C for 0–320 s ranges 1-0. • Mafart model properly describes lifespan of surviving L3 incubated in gastric juice. • Larvae are not able to penetrate into agar after >120 s at 50 °C (i.e. S ≤ 0.88). • Locomotor activity and respiration capacity are modified even at S close to 1. • Results provide data to characterize the risk when-in-doubt thermal situations. [ABSTRACT FROM AUTHOR]

The European conger, Conger conger, is a benthic marine fish species with a geographical distribution extending through the northeastern Atlantic and the Mediterranean. Despite being extensively distributed and widely appreciated by Spanish consumers, studies regarding parasite presence in this fish are scarce. In the present work, a hundred and eight specimens from the Mediterranean coast of northeastern Spain (Catalan waters) were surveyed for the presence of nematode parasites. Several species were morphologically identified: third-stage larvae of Anisakis type I (sensu Berland, 1961) (n = 131), third-stage larvae of Anisakis type II (sensu Berland, 1961) (n = 18), third- and fourth-stage larvae and adults of Hysterothylacium spp. (n = 48), adults of Cucullanus sp. (n = 391), and adults of Cristitectus congeri (n = 69). Moreover, some fish and decapode species were also observed as part of the host’s diet, with the most detected preys being Micromesistius poutassou, Sardina pilchardus, Macropipus sp., and Goneplax rhomboides. This represents the first survey of nematode parasites infecting C. conger from the northeastern Spanish Mediterranean waters. Among the parasite species detected, the presence of Anisakis species should be highlighted as the ingestion of C. conger parasitized with these larvae could potentially lead to anisakiasis in consumers.

We present a case of intussusception with complete small bowel obstruction caused by intestinal anisakidosis requiring surgical resection. A 30-year-old man presented with acute onset of severe abdominal pain 3 days after eating home-cured salmon gravlax. Despite surgery, the patient developed recurrent abdominal pain on two occasions with evidence of continued inflammation proximal to the surgical anastomosis. He was then treated with albendazole and prednisone, and symptoms improved. A decision was made to prophylactically treat two asymptomatic family members who also consumed home-cured gravlax with albendazole, resulting in one individual passing an intact Anisakis worm in her stool. We suggest that albendazole therapy could be considered as a therapy for continued symptoms of anisakidosis and postexposure prophylaxis of Anisakis larvae ingestion from a common source.

Infective third-stage larvae (L3) of the marine nematode Anisakis pegreffii cause inflammation and clinical symptoms in humans, their accidental host, that subside and self-resolve in a couple of weeks after L3 die. To characterise the differences in an early immune response of a marine vs. terrestrial host, we stimulated peripheral blood leukocytes (PBLs) of fish (paratenic host) and rat (accidental, human-model host) with A. pegreffii crude extract and analysed PBL transcriptomes 1 and 12 h post-stimulation. Fish and rat PBLs differentially expressed 712 and 493 transcripts, respectively, between 1 and 12 h poststimulation (false discovery rate, FDR <0.001, logFC >2). While there was a difference in the highest upregulated transcripts between two time-points, the same Gene Ontologies, biological processes (intracellular signal transduction, DNA-dependent transcription, and DNA-regulated regulation of transcription), and molecular functions (ATP and metal ion binding) were enriched in the two hosts, showing an incrementing dynamic between 1 and 12 h. This suggests that the two distinct hosts employ qualitatively different transcript cascades only to achieve the same effect, at least during an early innate immunity response. Activation of later immunity elements and/or a combination of other host's intrinsic conditions may contribute to the death of L3 in the terrestrial host. [ABSTRACT FROM AUTHOR]

The small pelagic European sardine presents high commercial and ecological values. Due to its cold-temperate water affinity, stocks are affected by global warming. Water temperature rise may change primary productivity patterns, negatively affecting fish condition and increasing parasite incidence. In this context, sardine health status was evaluated through the annual cycle on the Catalan Coast using thermal regimes comparison. Morphogravimetric parameters, sex and gonadal stages were assessed; infection by nematodes was characterised, and body condition was estimated by the Le Cren Factor and lipid content measured using a fish fat meter. Significant statistical differences were observed in spawning dynamics, body condition, and parasite infection between thermal regimes. Sardines from the colder north area had better condition and an earlier spawning, with lower parasite incidence (in terms of total prevalence, mean intensity and abundance) than those from the southern coast. Hysterothylacium spp. was the most abundant nematode, while Anisakis spp. prevalence was null in the two locations. Seasonal differences in nematode load were observed along the Catalan Coast, with lower prevalence during the summer and higher in winter-spring. Although previous studies have underestimated parasite influence on sardine health status, parasite abundance and sardine condition were negatively correlated. Seawater temperature and primary productivity are the proposed factors promoting differentiation in nematode infection and fish condition throughout the annual cycle and between locations. [ABSTRACT FROM AUTHOR]

Numerous marine fishes from the Algerian coast were examined for nematode parasites. Our study revealed five species of nematodes that were identified according to morphological characteristics: Anisakissimplex, Hysterothylacium aduncum, Hysterothylacium reliquens, Hysterothylacium fabri, Dichelyne pleuronectidis. D. pleuronectidis was newly collected from the study region. Four new host species were recorded for A. simplex, six for H. aduncum, and three for H. fabri. The infection rates observed were higher for Hysterothylacium and Dichelyne than Anisakis. The highest infection rate by Nematoda parasites were recorded for Trachinus draco L., Pagellus acarne (Risso) and Mullus barbatus L. (P = 100%, P = 53.33%, P = 42.5%), respectively. Nematoda larvae were found in body cavity and musculature. Histological changes associated with nematode musculature infestation revealed myodegeneration of fibers with a loss of striated texture and skin damage. [ABSTRACT FROM AUTHOR]

Spotted flounder (Citharus linguatula L.) caught in the Gulf of Cadiz (area FAO 27 ICES IXa) were examined for Anisakis larvae and to assess the possible risk of anisakiasis in humans through consumption of this fish. Larvae of the genera Anisakis and Hysterothylacium were identified in the analysis of 128 purchased fish specimens. All Anisakis larvae corresponded to type I. Molecular analysis showed the presence of A. pegreffii, A. simplex s.s., and recombinant genotype between the two. The prevalence of Anisakis was 9.4% with a mean intensity of 1.42, while for Hysterothylacium the values were 12.5% and 1.06. The length and weight of the fish, but not Fulton's condition factor, varied significantly between infected and uninfected fish. The prevalence of Anisakis increased with fish length, with no fish parasitized with Anisakis measuring less than 15.5 cm (2–2.5 years old), which is probably related to the reported dietary change of these fish at around 2 years of age. Fish not parasitized with any of these nematodes showed positive allometric growth, while those parasitized only with Anisakis showed negative allometric growth. When comparing both groups including only fish ≥ 15.5 cm (the smallest size of Anisakis-infected fish), the difference is shown to be statistically significant (p = 0.01), suggesting that Anisakis infection of spotted flounder negatively affects fish growth even when parasite intensity is low, which may have important economic repercussions. Finally, the low prevalence and, above all, intensity of Anisakis in these fish, as well as the habit of consuming this fish fried in oil in our geographical area, means that the risk of acquiring anisakiasis through consumption of this fish is low. [ABSTRACT FROM AUTHOR]

Simple Summary: Anisakidae is a family in the phylum Nematode, which is probably the most prevalent family of parasites found in marine mammals. These nematodes are colonizers of the digestive system of marine vertebrates that use different crustaceans and fish species as intermediate or paratenic hosts and humans as accidental hosts. Human anisakidosis, an infection caused by some species of the family Anisakidae, occurs when shellfish, particularly fish, contaminated with the infectious stage (third-stage larvae [L3]) of this parasite are consumed raw or undercooked. Data on the species of Anisakis found in fish in the waters of the Canary Islands and epidemiological data in general from this archipelago on this parasitic nematode are scarce, so the aim of this study was to provide these data on fish with an interest in consumption in the Canary Archipelago. Five species of Anisakis were identified, of which two have health relevance to humans. These findings are valuable for the safe consumption of fish by the population and for the knowledge of health authorities when it comes to a better diagnosis in hospitals and for future epidemiological and biomedical research. The study aimed to perform the molecular identification of Anisakis larvae in commercial fish from the coast of the Canary Islands and to provide data on their infection level for the host and the species of this nematode parasite that we could find in several species of commercial interest in the Canary Archipelago. Fish specimens (n = 172) from the Canary coasts were examined for parasites. In total, 495 larvae were identified; PCR was carried out for the entire ITS rDNA and cox2 mtDNA region, obtaining sixteen sequences for the entire ITS rDNA region and fifteen for the cox2 mtDNA, this being the first contribution of nucleotide sequences of Anisakis species of fish caught from the Canary Islands. An overall prevalence of 25% was obtained in the fish analyzed, and five species of Anisakis were identified, these being Anisakis simplex (s.s.), Anisakis pegreffii, Anisakis physeteris, Anisakis nascettii and Anisakis typica and the hybrid Anisakis simplex x Anisakis pegreffii. The results obtained in this study have relevance for public health, since the pathology will depend on the species of Anisakis, so it is important to know the health status of fish in the waters of the Canary Islands to assure a safer consumption and take adequate measures, in addition to the provision of epidemiological data. [ABSTRACT FROM AUTHOR]

Studying the genetic diversity of nematode parasite populations is crucial to gaining insight into parasite infection dynamics and informing parasite phylogeography. Anisakiasis is a zoonotic disease caused by the consumption of infectious third-stage larvae (L3) of Anisakis spp. carried by marine fish. In the present study, a total of 206 mitochondrial DNA sequences (cytochrome c oxidase 2, cox2) were used to study the genetic diversity, genetic structure, and historical demography of twelve A. pegreffii populations from Trichiurus japonicas along the coast of mainland China and Taiwan. Two distinct evolutionary lineages of A. pegreffii and no significant genealogical structures corresponding to sampling localities suggested that isolation in the marginal seas shaped their patterns of phylogeographic distribution along the coast of mainland China and Taiwan during glaciation with lower sea levels. Furthermore, pairwise FST values and AMOVA did not indicate any significant genetic differentiation among groups with no relation to the geographic area, which might be attributed to fewer barriers to gene flow as well as large population sizes. The results of the neutrality test, mismatch distribution, and Bayesian skyline plot analyses showed that entire population underwent population expansion during the late Pleistocene. Analysis of the demographic history revealed that A. pegreffii underwent historical lineage diversification and admixture due to secondary contact based on ABC analysis. The present research represents the first definitive population structure and demographic history across sampling locations of A. pegreffii along the coast of mainland China and Taiwan. [ABSTRACT FROM AUTHOR]

Fish meat represents an essential source of animal protein worldwide and possesses a significant nutritive value, especially in Egypt. Anisakid nematodes are the most abundant parasites among various species of marine fishes. These worms could alter the chemical properties of fish tissue reducing their quality. The current study aimed to analyze the presence of larvae in marine fish frequently consumed in Egyptian supermarkets, and to measure the chemical traits of fish, inferring the risk of infection and its impact on the fish quality. In total 435 specimens of three of the most consumed marine fish species in Alexandria, Egypt; chub mackerel (Scomber japonicus), Spanish mackerel (Scomber commerson), and Atlantic herring (Clupea harengus) were examined for Anisakid nematodes. The degree of infestation was categorized into a control group (completely free from Anisakis), a mild infection group (up to 15 larvae/100 g), a medium infection group (>15-30 larvae/100 g), and the high or heavy infection group (>30-50 larvae/100 g). The larvae were isolated, counted then fish tissues were subjected to chemical and molecular analysis. Analysis showed that the overall Anisakis infestation among the examined fish species was 27.1% (118/435). The Atlantic herring represented the highest parasitic infection with Anisakis larvae (37.3%), then came the chub mackerel (23.8%), and lastly the Spanish mackerel (23.5%). Regarding the chemical quality parameters of fish samples, Trimethylamine values of the heavy Anisakis-infested samples of all chubs, Spanish and herring samples were higher (mean values 11.38, 10.61, and 11.52 mg/100g, respectively) than the control and other groups with different degrees of Anisakis infestation. Also, histamine values followed the same manner in the highest infection group (mean values 4.38, 3.78, and 5.73 mg/100g, respectively). The degree of Anisakis infestation in marine water fish should be considered by marketers and consumers, as it has a crucial impact on the quality parameters of fish flesh. [ABSTRACT FROM AUTHOR]

Background: Anisakis spp. third-stage larvae (L3) are the causative agents of human zoonosis called anisakiasis. The accidental ingestion of L3 can cause acute and chronic inflammation at the gastric, intestinal, or ectopic levels. Despite its relevance in public health, studies on pathogenetic mechanisms and parasite-human interplay are scarce. The aim of this study was to investigate the human inflammatory response to different Anisakis vehicles of pathogenicity. Methods: Human colorectal adenocarcinoma (Caco-2) cells were exposed to Anisakis L3 (the initial contact with the host), extracellular vesicles (EVs, Anisakis–host communication), and crude extract (CE, the larval dying). The protein quantity and gene expression of two pro-inflammatory cytokines (IL-6 and IL-8) were investigated using an ELISA test (6 h and 24 h) and a qReal-Time PCR (1 h, 6 h, and 24 h), respectively. Results: The L3 and EVs induced a downregulation in both the Il-6 and Il-8 gene expression and protein quantity. On the contrary, the CE stimulated IL-6 gene expression and its protein release, not affecting IL-8. Conclusions: The Caco-2 cells seemed to not react to the exposure to the L3 and EVs, suggesting a parasite's immunomodulating action to remain alive in an inhospitable niche. Conversely, the dying larva (CE) could induce strong activation of the immune strategy of the host that, in vivo, would lead to parasite expulsion, eosinophilia, and/or granuloma formation. [ABSTRACT FROM AUTHOR]

Anisakis are foodborne parasites that opportunistically parasitize humans, leading to acute abdominal symptoms and allergies. Besides gastroscopy, no other diagnostic technique is available. Consequently, it is necessary to identify specific biomarkers and then develop molecular techniques for diagnosing Anisakis infection. In the present study, we used immunoproteomic and immunoinformatic approaches to identify sensitive antigens for diagnosing Anisakis pegreffii infection. A total of three proteins, including Ani609 (VDK51609), Ani941 (VDK75941), and AniS13, were identified based on immunoinformatic results. Then, the indirect ELISA method was developed based on the recombinant proteins, showing a similar diagnostic capability to that of parasitic soluble proteins. Next, a Gaussia luciferase immunoprecipitation assay (LIPS) was further developed upon the fusion of the proteins and Gaussia luciferase. The LIPS method indicated that A. pegreffii infection could be detected in rats as early as 1 week post infection, especially for Ani941. Overall, we identified the novel antigens using immunoproteomic and immunoinformatic approaches and then developed a sensitive method for diagnosing A. pegreffii infection, particularly for the early stage.

Patient aged 71 with a history of type 2 diabetes mellitus. He came to the emergency department for abdominal pain and vomiting. Laboratory tests showed an increase in acute phase reactants. Abdominal CT scan showed dilated jejunal loops, compatible with intestinal occlusion. Urgent intervention was performed, resecting the affected segment. The pathology report showed a prominent transmural inflammatory infiltrate and interstitial oedema, with moderate villous atrophy, identifying parasitic structures compatible with anisakis larvae (family Anisakidae). Given the mechanism of tissue invasion, the larvae are surrounded by a predominantly eosinophilic inflammatory infiltrate, organised as granulomas or abscesses.

Abstract The distribution of parasites in host populations is integral to simulations of parasite populations. We compared three methods to measure parasite aggregation, namely the Hoover, coefficient of variation and I10 indices, using field data from a range of fish parasites. These included anisakid nematodes, trypanorhynch cestodes and polyopisthocotylean monogeneans from 10 previously published studies and one unpublished study. Positive correlations among the three methods were high. Standard errors and estimated biases obtained by bootstrap methods were smallest for the Hoover index. There was no evidence for a bias–variance trade‐off. The analyses suggest that the Hoover index is to be preferred as a measure of aggregation although difficulties remain in deriving theoretical and operational definitions of aggregation.

Background and objectives: Uvaria scheffleri Diels (Annonaceae), Zanthoxylum chalybeum Engl. (Rutaceae), and Vepris dainelli (Pichi-Serm.) Kokwaro (Rutaceae) are medicinal plants traditionally used in Ethiopia against pathogenic infections. In the present study, the chemical composition, larvicidal activity, and cytotoxic effect of essential oils were investigated. Methods: Hydrodistillation technique was used to extract essential oils. In vitro larvicidal activity against Anisakis L3 larvae was tested in marinated solutions. MTT assay was used to assess the cytotoxicity. Results: The yields (v/w) of essential oils obtained from U. scheffleri roots, Z. chalybeum, and V. dainelli fruits were 0.5, 2.7, and 2.0 %, respectively. Gas chromatography-mass spectrometry analysis of essential oils revealed a total of 58, 18, and 20 chemical constituents, representing 97.6, 99.6, and 98.8 % of the oil contents, respectively. Tricyclo [5.3.0.0(3, 9)] decane was identified to be the principal constituent in the essential oils of Z. chalybeum (82.8%) and V. dainelli (69.8%), reported herein for the first time. Essential oils of Z. chalybeum, U. scheffleri, and V. dainelli displayed a dose-dependent larvicidal activity with LT100 values of 3 h, 5 h, and 5 h for 5% concentrations, respectively. The cytotoxicity study of essential oils on VERO cells showed moderate toxicity with IC50 values of 65.46 µg/mL, 83.88 µg/mL, and 96.82 µg/mL, respectively. Conclusion: The results obtained revealed that the studied essential oils could serve as larvicidal agents in treating human anisakidosis. The observed weak cytotoxicity at low concentrations points out the possibility of developing effective and safe botanical larvicides.

Infective third-stage larvae (L3) of the marine nematode Anisakis pegreffii cause inflammation and clinical symptoms in humans, their accidental host, that subside and self-resolve in a couple of weeks after L3 die. To characterise the differences in an early immune response of a marine vs. terrestrial host, we stimulated peripheral blood leukocytes (PBLs) of fish (paratenic host) and rat (accidental, human-model host) with A. pegreffii crude extract and analysed PBL transcriptomes 1 and 12 h post-stimulation. Fish and rat PBLs differentially expressed 712 and 493 transcripts, respectively, between 1 and 12 h post-stimulation (false discovery rate, FDR 2). While there was a difference in the highest upregulated transcripts between two time-points, the same Gene Ontologies, biological processes (intracellular signal transduction, DNA-dependent transcription, and DNA-regulated regulation of transcription), and molecular functions (ATP and metal ion binding) were enriched in the two hosts, showing an incrementing dynamic between 1 and 12 h. This suggests that the two distinct hosts employ qualitatively different transcript cascades only to achieve the same effect, at least during an early innate immunity response. Activation of later immunity elements and/or a combination of other host’s intrinsic conditions may contribute to the death of L3 in the terrestrial host.

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Parasite biodiversity in cetaceans represents a neglected component of the marine ecosystem. This study aimed to investigate the distribution and genetic diversity of anisakid nematodes of the genus Anisakis sampled in cetaceans from the Northeast Atlantic Ocean and the Mediterranean Sea. A total of 478 adults and pre-adults of Anisakis spp. was identified by a multilocus genetic approach (mtDNA cox2, EF1 α − 1 nDNA and nas 10 nDNA gene loci) from 11 cetacean species. A clear pattern of host preference was observed for Anisakis spp. at cetacean family level: A. simplex (s.s.) and A. pegreffii infected mainly delphinids; A. physeteris and A. brevispiculata were present only in physeterids, and A. ziphidarum occurred in ziphiids. The role of cetacean host populations from different waters in shaping the population genetic structure of A. simplex (s.s.), A. pegreffii and A. physeteris was investigated for the first time. Significant genetic sub-structuring was found in A. simplex (s.s.) populations of the Norwegian Sea and the North Sea compared to those of the Iberian Atlantic, as well as in A. pegreffii populations of the Adriatic and the Tyrrhenian Seas compared to those of the Iberian Atlantic waters. Substantial genetic homogeneity was detected in the Mediterranean Sea population of A. physeteris. This study highlights a strong preference by some Anisakis spp. for certain cetacean species or families. Information about anisakid biodiversity in their cetacean definitive hosts, which are apex predators of marine ecosystems, acquires particular importance for conservation measures in the context of global climate change phenomena. [ABSTRACT FROM AUTHOR]

Simple Summary: The European pilchard is one of the most frequently consumed fish species in Mediterranean countries, especially in Italy and Spain, and has been reported as the cause of at least eight human anisakidosis cases in Spain since 1991, the parasitic disease caused by the ingestion of fish or cephalopods infested by the larval stage of anisakid nematodes. With the aim to shed light on the potential human parasitosis risk posed by these nematode larvae, we helminthologically analyzed a total of 350 sardines (European pilchard) captured in the Atlantic Ocean (175 sardines) and the Mediterranean Sea (175 specimens), acquired in various Spanish nationwide supermarket chains. The statistical analysis of some helminth parameters revealed a higher presence of nematodes belonging to the genus Hysterothylacium (frequency of parasitation of 24.29%; total mean parasite burden of 2.36), usually considered non-parasitic for humans (only three cases reported worldwide), when compared to nematodes of the genus Anisakis (5.71%; 0.16). The human anisakidosis risk after the consumption of raw or undercooked sardines and the role of Hysterothylacium, the most frequent nematode, is discussed, providing information to consumers. To avoid human infection by anisakid larval nematodes, the established preventive measures are confirmed and new ones are proposed. The European pilchard is one of the most frequently consumed fish species in Mediterranean countries, especially in Italy and Spain, and has been reported as the cause of at least eight human anisakidosis cases in Spain. With the aim to shed light on the potential human parasitosis risk posed by nematode larvae belonging to families Anisakidae or Raphidascarididae, a total of 350 sardines captured in the Atlantic Ocean (175 specimens) and the Mediterranean Sea (175 specimens), acquired in various Spanish nationwide supermarket chains, were helminthologically analyzed. The statistical analysis of some helminth parameters revealed a higher presence of nematodes belonging to the genus Hysterothylacium (prevalence 24.29%; mean abundance of 2.36), usually considered non-parasitic for humans (only three cases reported worldwide), when compared to nematodes of the genus Anisakis (5.71%; 0.16). The human anisakidosis risk after the consumption of raw or undercooked sardines and the role of Hysterothylacium, the most frequent nematode, is discussed, providing information to consumers. To avoid human infection by anisakid larval nematodes, the established preventive measures are confirmed and new ones are proposed, such as the consumption of sardines preferably caught in the Mediterranean and of small-sized specimens available, and the immediate evisceration after fishing. [ABSTRACT FROM AUTHOR]

The recent advances in molecular methods and data processing have facilitated research on anisakid nematodes. While most research efforts were made regarding the genus Anisakis, since this genus is held responsible for the majority of reported clinical signs, there is still a demand for data on the genus Pseudoterranova. Several case studies of severe invasive anisakidosis affecting various organs caused by species of the P. decipiens complex have been described. To better understand the way these parasites might infest their fish host, we examined whether parasite location within the fish host affects gene expression. A de novo assembly of the transcriptome of Pseudoterranova bulbosa, isolated from North Atlantic cod, was analysed for patterns of differential gene expression between samples taken from liver and viscera. We additionally searched for homologs to known nematode allergens, to give a first estimate of the potential allergenicity of P. bulbosa. There was a subtle difference in the gene expression of samples taken from liver and viscera. Seventy genes were differentially expressed, 32 genes were upregulated in parasites isolated from liver and 38 genes were upregulated in parasites from viscera. Homologs of five nematode allergens were identified among the genes expressed by P. bulbosa. Our transcriptome of P. bulbosa will be a valuable resource for further meta‐analyses and resequencing projects. [ABSTRACT FROM AUTHOR]

Purpose: This research was performed with the aim of hygienic tracking for fishborne parasitic contamination imported by Jack mackerel fish from certain parts of the world in a fish processing unit during a health inspection in the north region of Iran in the summer of the year 2019. Methods: A sample of 150 jack mackerel fish specimens was selected at random. All the fish had the same length and weight sizes at average measures of 53.6 cm and 2.04 kg. The cysts consisting of robust parasites seen on mesentery and muscles were then removed larval from their locality and placed in small glass jars containing 10% formalin and transferred to the lab. The results: A total of 100% of Jack Mackerel (Trachurus symmetricus) fish cargo, as a portion of human food, imported from New Zealand were severely contaminated with Anisakis sp. worm parasite. The parasite intensity ranges were between 25 and 70 individuals per fish, and the total of parasites was 7125 individuals. The mean intensity reached 47.5. The encysted parasite specimens were observed in the muscles, mesentery, and peritoneum of viscera around the abdominal cavity of mackerel whereas seeing as twisted third-stage larvae. Conclusion: As an aspect of human sanitary, the Anisakis species due to being zoonoses has significant importance. For this reason, people should avoid consuming raw or semi-cooked marine fish. The present study is the first available report of Anisakis sp. contamination in Jack mackerel imported to Iran. [ABSTRACT FROM AUTHOR]